function openwindow(url,name,options) {
	newwin=window.open(url,name,options);
	newwin.focus();
}

function openCentered (url, width, height, windowName, featureString) {
	if (!windowName) windowName = '';
	if (!featureString)	featureString = '';
	else
	featureString = ',' + featureString;
	var x = Math.round((screen.availWidth - width) / 2);
	var y = Math.round((screen.availHeight - height) / 2);
	featureString = 'left=' + x + ',top=' + y + ',width=' + width + ',height=' + height + featureString;
	newwin = open (url, windowName, featureString);
	newwin.focus();
}